The correct answer as to which has the highest species richness would be an ecosystem with 30 species with varying numbers of each population.
The species richness of an ecosystem literally refers to the number of unique species in that ecosystem irrespective of the population size of each of the species. For example, an ecosystem with 20 species each with a population size of 50 is richer in species than an ecosystem with 10 species each with a population size of 200. This is why the species richness of an ecosystem is one of the attributes used in measuring the diversity of that ecosystem.
Hence, an ecosystem with 30 species is richer than those with 25, 15, and 5 irrespective of the population size of each species.
More on species richness can be found here: https://brainly.com/question/13259455
